PHILADELPHIA -- On his first snap as part of an NFL defense, Philadelphia Eagles rookie cornerback Sidney Jones on Sunday crouched into an athletic stance and stared at three-time Pro Bowl receiver Dez Bryant.

The Cowboys didn't throw toward Bryant on that third-down play in the first quarter, but the moment still held great significance for Jones. It's wasn't because the second-round pick out of Washington was overwhelmed or awed by the thought of guarding Bryant in press coverage; it's that he spent so long without defending any receiver.

Jones tore his Achilles during Washington's Pro Day on March 10. The Eagles decided to draft him anyway, using the 43rd overall selection in April on the talented corner who at the time had barely begun a long rehab process. For month and months, Jones studied, worked with trainers and watched his Eagles teammates take the field without him.

The game against Dallas offered Jones an ideal opportunity to see his first live action. With the NFC's No. 1 seed locked up, the Eagles (13-3) couldn't gain much from a victory and rested several defensive starters against Dallas (9-7).

Jones wound up making two tackles and playing a variety of roles before he left Sunday's game at the start of the fourth quarter with cramps. Afterward, Jones said his left quad and back were tightening up at the time, but he felt fine after some mild treatment, and his Achilles never bothered him during the game.

"Everything is perfect," he said.

Jones played a few snaps in the slot, at outside cornerback and on punt coverage during the loss to the Cowboys and seemed to hold his own while doing "a little bit of everything" on defense. He didn't suffer many noticeable breakdowns in coverage but did allow Cowboys running back Ezekiel Elliott to get to the edge and pick up a first down at one point.

Fourth-year defensive back Jaylen Watkins said Jones played well and added that the failure to bring Elliott down on that run was a natural misstep for a rookie in his debut. It's difficult to judge angels after missing so much time on the field, Watkins explained.

Starting cornerback Ronald Darby, who missed eight weeks this season with a dislocated ankle, said Jones' play was especially promising considering the circumstances.

"He's been out for a year," Darby said. "To come out there the last game of the season, in this type of weather (temperatures were below 20 degrees), the plays he made, I was really impressed with him. The guys he was going up against have been out on the field since OTAs, the whole season, and he went out there, made some plays."

It's unlikely Jones will serve in a large role on the defense when the Eagles open postseason play by hosting an NFC divisional round matchup in two weeks, because the team has starters in place. But Philly drafted Jones with the idea that he'd develop into an impact player, and Sunday marked a hefty step toward that goal.

Whether he steps onto the field in a key spot in the playoffs or doesn't see action again until next year, Jones said his goal moving forward is to play with more calmness and confidence. He's already made his debut, already defended a Pro Bowl receiver, already battled back from a serious injury -- now he just needs to master the smaller tasks.

"Just getting use to it," Jones said. "Just slowing the game down mentally. My first game, was very anxious and excited, so just getting used to the little details."